The discovery, published today in Physical Review Letters, identifies an intermediate mass black hole. The discovery serves as a connector, the missing link, between known categories of black holes: smaller black holes known as stellar mass black holes, and the largest black holes known as supermassive black holes. Researchers observed the black hole using twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo gravitational-wave detector in Italy. These detectors are calibrated to sense tiny changes of distances on earth that are then interpreted through algorithms to make sense of the cosmic communication.